1. Field of the Invention
The present invention relates to an image pickup apparatus having an imaging element with a first pixel group that realizes a pupil-dividing function.
2. Description of the Related Art
Some of imaging elements have specific pixels (pixels for phase difference AF) for performing autofocus control with a phase difference detection system (hereinafter, also referred to as a “phase difference AF”).
For instance, Japanese Published Patent Application No. 2008-147821 discloses an image pickup apparatus provided with an imaging element having a plurality of pixel pairs for phase difference AF in which the centers of openings of the respective light-shielding plates are oppositely biased from each other with respect to the center of a microlens (hereinafter, also referred to as an imaging element with phase-difference detection function). Such an image pickup apparatus is configured such that a distance from a subject can be performed by allowing pixels for phase difference AF to receive light fluxes passed through a pair of portion areas on an exit pupil of a photographic lens.